John Cho? Really? Not who I'd have gone for as a casting choice.
So, let's take the "Ree woke" goggles off for a minute here.
The casting's not that great for utterly non-woke reasons by not properly looking at each character and their traits, so assuming a smallish budget I'll throw down my own semi-fantasy casting here.
Spike Spiegel is probably East Asian. Being based on Yusaku Matsuda n all. So casting an East Asian actor into this role makes a lot of sense. Cho's a "known name" in various geekdom circles and certainly the "correct" ones for the contacts, so is using (what's left of) his star power.
I'd rather like Simu Liu for Spike, who certainly has the style points and correct body to pull it off. He also has the range to do serious and more lighthearted roles.
Jet Black was voiced by Beau Billingslea, so recasting a black actor there really isn't some great surprise. Shakir's a pretty ok actor and has had very steady work throughout his career, which is not something people can pull off.
I'd have preferred someone who could pull off the same towering look as Jet though, which as much as I do like Shakir he doesn't manage. So maybe another curve ball and taking someone from the wrestling world? How about I throw one really out there and we get Mark Henry, the former WWE wrestler in for Jet? 6'4, hulking weight lifter who could use wrestling moves in fist fights. Man, that would be pretty sweet.
Faye Valentine is where things start falling apart though Daniella Pineda is the first odd duck out with no real reason to cast her. There's nothing to pick up on as, again, Faye should be some kind of Asian Actress. I'd go for someone who looks a little spoiled but will probably break your neck.
So JuJu Chan. Worked on a few things and knows MMA. You could even have a classic Faye moment where she looks spoiled brat/seducing someone before beating the ever loving shit out of them.
Vicious with Alex Hassell is perhaps the only one I can give a vague pass to. He's a solid British actor, he's trodden the boards and was even cast as Henry in Henry V by the Royal Shakespeare Company. RSC don't do shit casting, and they certainly don't put shit actors into the lead roles. As it currently stands, Hassell's going to steal the show.